When an atmospheric river hits the lower Russian River, the roof and the river become linked problems. The same storm that drops limbs on roofs can raise the river enough to close the roads roofers need.
The river levels that cut off access
From the CNRFC's impact list for the Guerneville gauge (CNRFC):
- 33 ft: Highway 116 at Drake Road in Guerneville closes.
- 39 ft: River Road floods in Hacienda; Canyon 7 Road in Rio Nido floods.
- 41.5 ft: River Road closes in Guerneville.
- 44 to 46 ft: Highway 116 west of town closes; much of downtown Guerneville floods.
In February 2019 the river crested at 45.38 feet, and the NWS counted roughly 2,000 properties with some damage in the Guerneville and Monte Rio area (NWS).
Before the storm
- Get damaged areas repaired or tarped before the river forecast rises. Watch CNRFC's forecast and Sonoma Water's flood information.
- Clear needles and debris from gutters and valleys if you can do so safely.
- Have a tree professional look at large limbs over the roof.
- Sign up for SoCoAlert.
During and after
- Stay off the roof in wind and rain. Contain leaks inside and document damage.
- Once roads open, expect demand. Book early and verify the license on CSLB. Unlicensed contracting in a declared disaster area is a felony (CSLB).
- A professional tarp bridges the gap to a permanent repair.
Want a local pro to take a look?It's free for homeowners and there's no obligation.
Permits
Guerneville, Monte Rio and Rio Nido are unincorporated; Permit Sonoma handles permits.
If floodwater came in, see Russian River flood cleanup and mold after a Russian River flood.
Sources
- CNRFC: Russian River at Guerneville
- NWS: Historic flooding across the North Bay, Feb 2019
- Sonoma Water: Flood forecast
- SoCoAlert sign-up
- CSLB: license check
- CSLB: disaster information
- Permit Sonoma
Sources checked October 18, 2026.
Frequently asked questions
Can roofers reach Guerneville during a flood?
Not when roads are closed. Calling before the river rises gets you in line for when access returns.
Is moss on my roof a problem?
It can be. Moss holds moisture and lifts shingle edges. Remove it gently or have a roofer do it; pressure washing can damage roofing.